This first of two volumes brings together invited papers of the 32nd International Wittgenstein Symposium (Kirchberg/W. (Austria), 2009). The relation between language and the world was undoubtedly one if not the central issue in Wittgenstein's whole philosophical oeuvre. His one hundred and twentieth birthday provided an occasion for foregrounding this aspect of his work. A special workshop was dedicated to new aspects of Wittgenstein's Nachlass. In this volume Frank Cioffi, Peter Hacker, Ian Hacking, Roy Harris, Lars Hertzberg, Jaakko Hintikka, Marie McGinn, Danièle Moyal-Sharrock, Hans Sluga among others provide substantial contributions on various aspects of Wittgenstein's writings such as the philosophy of mathematics, the problem of rule following or the relation between meaning and use.